<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Dojo
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Data.php 18951 2009-11-12 16:26:19Z alexander $
 */

/**
 * dojo.data support for Zend Framework
 *
 * @uses       ArrayAccess
 * @uses       Iterator
 * @uses       Countable
 * @package    Zend_Dojo
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Dojo_Data implements ArrayAccess,Iterator,Countable
{
	/**
	 * Identifier field of item
	 * @var string|int
	 */
	protected $_identifier;

	/**
	 * Collected items
	 * @var array
	 */
	protected $_items = array();

	/**
	 * Label field of item
	 * @var string
	 */
	protected $_label;

	/**
	 * Data container metadata
	 * @var array
	 */
	protected $_metadata = array();

	/**
	 * Constructor
	 *
	 * @param  string|null $identifier
	 * @param  array|Traversable|null $items
	 * @param  string|null $label
	 * @return void
	 */
	public function __construct($identifier = null, $items = null, $label = null)
	{
		if (null !== $identifier) {
			$this->setIdentifier($identifier);
		}
		if (null !== $items) {
			$this->setItems($items);
		}
		if (null !== $label) {
			$this->setLabel($label);
		}
	}

	/**
	 * Set the items to collect
	 *
	 * @param array|Traversable $items
	 * @return Zend_Dojo_Data
	 */
	public function setItems($items)
	{
		$this->clearItems();
		return $this->addItems($items);
	}

	/**
	 * Set an individual item, optionally by identifier (overwrites)
	 *
	 * @param  array|object $item
	 * @param  string|null $identifier
	 * @return Zend_Dojo_Data
	 */
	public function setItem($item, $id = null)
	{
		$item = $this->_normalizeItem($item, $id);
		$this->_items[$item['id']] = $item['data'];
		return $this;
	}

	/**
	 * Add an individual item, optionally by identifier
	 *
	 * @param  array|object $item
	 * @param  string|null $id
	 * @return Zend_Dojo_Data
	 */
	public function addItem($item, $id = null)
	{
		$item = $this->_normalizeItem($item, $id);

		if ($this->hasItem($item['id'])) {
			require_once 'Zend/Dojo/Exception.php';
			throw new Zend_Dojo_Exception('Overwriting items using addItem() is not allowed');
		}

		$this->_items[$item['id']] = $item['data'];

		return $this;
	}

	/**
	 * Add multiple items at once
	 *
	 * @param  array|Traversable $items
	 * @return Zend_Dojo_Data
	 */
	public function addItems($items)
	{
		if (!is_array($items) && (!is_object($items) || !($items instanceof Traversable))) {
			require_once 'Zend/Dojo/Exception.php';
			throw new Zend_Dojo_Exception('Only arrays and Traversable objects may be added to ' . __CLASS__);
		}

		foreach ($items as $item) {
			$this->addItem($item);
		}

		return $this;
	}

	/**
	 * Get all items as an array
	 *
	 * Serializes items to arrays.
	 *
	 * @return array
	 */
	public function getItems()
	{
		return $this->_items;
	}

	/**
	 * Does an item with the given identifier exist?
	 *
	 * @param  string|int $id
	 * @return bool
	 */
	public function hasItem($id)
	{
		return array_key_exists($id, $this->_items);
	}

	/**
	 * Retrieve an item by identifier
	 *
	 * Item retrieved will be flattened to an array.
	 *
	 * @param  string $id
	 * @return array
	 */
	public function getItem($id)
	{
		if (!$this->hasItem($id)) {
			return null;
		}

		return $this->_items[$id];
	}

	/**
	 * Remove item by identifier
	 *
	 * @param  string $id
	 * @return Zend_Dojo_Data
	 */
	public function removeItem($id)
	{
		if ($this->hasItem($id)) {
			unset($this->_items[$id]);
		}

		return $this;
	}

	/**
	 * Remove all items at once
	 *
	 * @return Zend_Dojo_Data
	 */
	public function clearItems()
	{
		$this->_items = array();
		return $this;
	}


	/**
	 * Set identifier for item lookups
	 *
	 * @param  string|int|null $identifier
	 * @return Zend_Dojo_Data
	 */
	public function setIdentifier($identifier)
	{
		if (null === $identifier) {
			$this->_identifier = null;
		} elseif (is_string($identifier)) {
			$this->_identifier = $identifier;
		} elseif (is_numeric($identifier)) {
			$this->_identifier = (int) $identifier;
		} else {
			require_once 'Zend/Dojo/Exception.php';
			throw new Zend_Dojo_Exception('Invalid identifier; please use a string or integer');
		}

		return $this;
	}

	/**
	 * Retrieve current item identifier
	 *
	 * @return string|int|null
	 */
	public function getIdentifier()
	{
		return $this->_identifier;
	}


	/**
	 * Set label to use for displaying item associations
	 *
	 * @param  string|null $label
	 * @return Zend_Dojo_Data
	 */
	public function setLabel($label)
	{
		if (null === $label) {
			$this->_label = null;
		} else {
			$this->_label = (string) $label;
		}
		return $this;
	}

	/**
	 * Retrieve item association label
	 *
	 * @return string|null
	 */
	public function getLabel()
	{
		return $this->_label;
	}

	/**
	 * Set metadata by key or en masse
	 *
	 * @param  string|array $spec
	 * @param  mixed $value
	 * @return Zend_Dojo_Data
	 */
	public function setMetadata($spec, $value = null)
	{
		if (is_string($spec) && (null !== $value)) {
			$this->_metadata[$spec] = $value;
		} elseif (is_array($spec)) {
			foreach ($spec as $key => $value) {
				$this->setMetadata($key, $value);
			}
		}
		return $this;
	}

	/**
	 * Get metadata item or all metadata
	 *
	 * @param  null|string $key Metadata key when pulling single metadata item
	 * @return mixed
	 */
	public function getMetadata($key = null)
	{
		if (null === $key) {
			return $this->_metadata;
		}

		if (array_key_exists($key, $this->_metadata)) {
			return $this->_metadata[$key];
		}

		return null;
	}

	/**
	 * Clear individual or all metadata item(s)
	 *
	 * @param  null|string $key
	 * @return Zend_Dojo_Data
	 */
	public function clearMetadata($key = null)
	{
		if (null === $key) {
			$this->_metadata = array();
		} elseif (array_key_exists($key, $this->_metadata)) {
			unset($this->_metadata[$key]);
		}
		return $this;
	}

	/**
	 * Load object from array
	 *
	 * @param  array $data
	 * @return Zend_Dojo_Data
	 */
	public function fromArray(array $data)
	{
		if (array_key_exists('identifier', $data)) {
			$this->setIdentifier($data['identifier']);
		}
		if (array_key_exists('label', $data)) {
			$this->setLabel($data['label']);
		}
		if (array_key_exists('items', $data) && is_array($data['items'])) {
			$this->setItems($data['items']);
		} else {
			$this->clearItems();
		}
		return $this;
	}

	/**
	 * Load object from JSON
	 *
	 * @param  string $json
	 * @return Zend_Dojo_Data
	 */
	public function fromJson($json)
	{
		if (!is_string($json)) {
			require_once 'Zend/Dojo/Exception.php';
			throw new Zend_Dojo_Exception('fromJson() expects JSON input');
		}
		require_once 'Zend/Json.php';
		$data = Zend_Json::decode($json);
		return $this->fromArray($data);
	}

	/**
	 * Seralize entire data structure, including identifier and label, to array
	 *
	 * @return array
	 */
	public function toArray()
	{
		if (null === ($identifier = $this->getIdentifier())) {
			require_once 'Zend/Dojo/Exception.php';
			throw new Zend_Dojo_Exception('Serialization requires that an identifier be present in the object; first call setIdentifier()');
		}

		$array = array(
            'identifier' => $identifier,
            'items'      => array_values($this->getItems()),
		);

		$metadata = $this->getMetadata();
		if (!empty($metadata)) {
			foreach ($metadata as $key => $value) {
				$array[$key] = $value;
			}
		}

		if (null !== ($label = $this->getLabel())) {
			$array['label'] = $label;
		}

		return $array;
	}

	/**
	 * Serialize to JSON (dojo.data format)
	 *
	 * @return string
	 */
	public function toJson()
	{
		require_once 'Zend/Json.php';
		return Zend_Json::encode($this->toArray());
	}

	/**
	 * Serialize to string (proxy to {@link toJson()})
	 *
	 * @return string
	 */
	public function __toString()
	{
		return $this->toJson();
	}

	/**
	 * ArrayAccess: does offset exist?
	 *
	 * @param  string|int $offset
	 * @return bool
	 */
	public function offsetExists($offset)
	{
		return (null !== $this->getItem($offset));
	}

	/**
	 * ArrayAccess: retrieve by offset
	 *
	 * @param  string|int $offset
	 * @return array
	 */
	public function offsetGet($offset)
	{
		return $this->getItem($offset);
	}

	/**
	 * ArrayAccess: set value by offset
	 *
	 * @param  string $offset
	 * @param  array|object|null $value
	 * @return void
	 */
	public function offsetSet($offset, $value)
	{
		$this->setItem($value, $offset);
	}

	/**
	 * ArrayAccess: unset value by offset
	 *
	 * @param  string $offset
	 * @return void
	 */
	public function offsetUnset($offset)
	{
		$this->removeItem($offset);
	}

	/**
	 * Iterator: get current value
	 *
	 * @return array
	 */
	public function current()
	{
		return current($this->_items);
	}

	/**
	 * Iterator: get current key
	 *
	 * @return string|int
	 */
	public function key()
	{
		return key($this->_items);
	}

	/**
	 * Iterator: get next item
	 *
	 * @return void
	 */
	public function next()
	{
		return next($this->_items);
	}

	/**
	 * Iterator: rewind to first value in collection
	 *
	 * @return void
	 */
	public function rewind()
	{
		return reset($this->_items);
	}

	/**
	 * Iterator: is item valid?
	 *
	 * @return bool
	 */
	public function valid()
	{
		return (bool) $this->current();
	}

	/**
	 * Countable: how many items are present
	 *
	 * @return int
	 */
	public function count()
	{
		return count($this->_items);
	}

	/**
	 * Normalize an item to attach to the collection
	 *
	 * @param  array|object $item
	 * @param  string|int|null $id
	 * @return array
	 */
	protected function _normalizeItem($item, $id)
	{
		if (null === ($identifier = $this->getIdentifier())) {
			require_once 'Zend/Dojo/Exception.php';
			throw new Zend_Dojo_Exception('You must set an identifier prior to adding items');
		}

		if (!is_object($item) && !is_array($item)) {
			require_once 'Zend/Dojo/Exception.php';
			throw new Zend_Dojo_Exception('Only arrays and objects may be attached');
		}

		if (is_object($item)) {
			if (method_exists($item, 'toArray')) {
				$item = $item->toArray();
			} else {
				$item = get_object_vars($item);
			}
		}

		if ((null === $id) && !array_key_exists($identifier, $item)) {
			require_once 'Zend/Dojo/Exception.php';
			throw new Zend_Dojo_Exception('Item must contain a column matching the currently set identifier');
		} elseif (null === $id) {
			$id = $item[$identifier];
		} else {
			$item[$identifier] = $id;
		}

		return array(
            'id'   => $id,
            'data' => $item,
		);
	}
}
